of: Allow busses with #size-cells=0
It's quite legitimate for a DT node to specify #size-cells=0. One example
is a node that's used to collect a number of non-memory-mapped devices.
In that scenario, there may be multiple child nodes with the same name
(type) thus necessitating the use of unit addresses in node names, and
reg properties:
/ {
regulators {
compatible = "simple-bus";
#address-cells = <1>;
#size-cells = <0>;
regulator@0 {
compatible = "regulator-fixed";
reg = <0>;
...
};
regulator@1 {
compatible = "regulator-fixed";
reg = <1>;
...
};
...
};
};
However, #size-cells=0 prevents translation of reg property values into
the parent node's address space. In turn, this triggers the kernel to
emit error messages during boot, such as:
prom_parse: Bad cell count for /regulators/regulator@0
To prevent printing these error messages for legitimate DT content, a
number of changes are made:
1) of_get_address()/of_get_pci_address() are modified only to validate
the value of #address-cells, and not #size-cells.
2) of_can_translate_address() is added to indicate whether address
translation is possible.
3) of_device_make_bus_id() is modified to name devices based on the
translated address only where possible, and otherwise fall back to
using the (first cell of the) raw untranslated address.
4) of_device_alloc() is modified to create memory resources for a device
only if the address can be translated into the CPU's address space.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index e44f8c2..9bdeaf30 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -78,6 +78,7 @@
struct device_node *node = dev->of_node;
const u32 *reg;
u64 addr;
+ const __be32 *addrp;
int magic;
#ifdef CONFIG_PPC_DCR
@@ -105,7 +106,15 @@
*/
reg = of_get_property(node, "reg", NULL);
if (reg) {
- addr = of_translate_address(node, reg);
+ if (of_can_translate_address(node)) {
+ addr = of_translate_address(node, reg);
+ } else {
+ addrp = of_get_address(node, 0, NULL, NULL);
+ if (addrp)
+ addr = of_read_number(addrp, 1);
+ else
+ addr = OF_BAD_ADDR;
+ }
if (addr != OF_BAD_ADDR) {
dev_set_name(dev, "%llx.%s",
(unsigned long long)addr, node->name);
@@ -140,8 +149,9 @@
return NULL;
/* count the io and irq resources */
- while (of_address_to_resource(np, num_reg, &temp_res) == 0)
- num_reg++;
+ if (of_can_translate_address(np))
+ while (of_address_to_resource(np, num_reg, &temp_res) == 0)
+ num_reg++;
num_irq = of_irq_count(np);
/* Populate the resource table */